1. Field of the Invention
The present invention relates in general to a digital versatile disc (referred to hereinafter as DVD), and more particularly to an apparatus and a method for generating a block synchronous signal for a DVD, in which a block synchronous signal compensator compensates for an error in a sector identifier (referred to hereinafter as ID) indicative of the head of data to correct it.
2. Description of the Prior Art
In a conventional DVD, only an error in an error correction code block is corrected while an error in an ID indicative of the head of the error correction code block is not corrected. For this reason, highly reliable data cannot be obtained.
On the other hand, a clock generator circuit for generating a clock for the recording and reproduction of data on/from a recording medium such as an optical disc is shown in U.S. Pat. No. 4,982,110, issued to Pioneer Electronic Corporation, Tokyo, Japan. In order to overcome a conventional problem that a synchronous signal cannot be detected when a pulse due to noises, defects, or the like is produced between two edge pulses constituting the synchronous signal, the clock generator circuit employs a synchronous signal detector and a phase comparator for the stable detection of the synchronous signal. The clock generator circuit can accurately generate the clock with no variation in phase due to a change in temperature and perform the phase comparison on the basis of only single edge information.
Further, the above patent relates to a synchronous signal detection apparatus for a disc player, which comprises synchronous signal detection means for sensing a time interval between a first edge pulse and a second edge pulse of an input signal and detecting the second edge pulse as a synchronous signal when the time interval is greater than a predetermined time interval. The synchronous signal detection apparatus further comprises determination means for determining whether or not the synchronous signal is detected in a stable manner, and input signal transmission means for inhibiting transmission of the input signal to the synchronous signal detection means for a predetermined interval of time subsequent to the first edge pulse and before the second edge pulse while it is determined that the synchronous signal is detected in the stable manner, and transmitting the input signal to the synchronous signal detection means for the predetermined interval of time between the first and second edge pulses while it is determined that the synchronous signal is not detected in the stable manner.
The above-mentioned synchronous signal detection apparatus can detect the synchronous signal even when an abnormal pulse due to noises, defects, temperature variations, or the like is produced between the two edge pulses constituting the synchronous signal. However, the above-mentioned conventional synchronous signal detection apparatus cannot detect and correct an error in an ID indicative of the head of data using the synchronous signal, thus resulting in no improvement in data reliability.